Tuyere diameter reducer



Patentecl July 20, 1937 EUNITED sTATEs PATENT OFFICE Frederick H. N. Gerwg, North Braddock, Pa.

Application October 31, 1936, Serial No. 108,670

3 claims.

This invention relates to means for controlling the air blast introduced into a blast furnace, and particularly relates to means for reducing the diameter of a tuyre nozzle.

In actual use the amount of iron desired to be produced from a blast furnace often varies widely. When the amount of iron produced by the blast furnace is reduoed, then the air blast supplied to the urnace must be Varied correspondingly if the furnace is to have a good yield and be kept in good condition.

The object of this invention is to provide an inexpensive, easily insertable bushing which is adapted to be fitted in the noZZle of a tuyre to reduce the effective diameter thereof, and consequently reduce the air blast entering the furnace through said tuyre.

Another object is to provide a reducing bushing designed and adapted to fit the interier end of the tuyre so as to maintain the necessary velocity of the blast required and to provide a sufficiently positive horizontal penetration of the blast to insure a "goodworkng" furnace by pre- Venting the blast from traveling vertically along the bosh wall.

The above and further objects wil be apparent from the enclosed drawing in which:

Figure l is a longitudinal sectional elevation of one embodiment of my invention in position in a blast furnace;

Figure 2 is an enlarged elevation, partly broken away, of the embodiment of my invention shown in Figure 1 mounted in a tuyre; and

Figure 3 is an end elevation of the embodiment of my invention shown in Figure 2.

Referring more particularly to the accompanying drawing, the numeral 2 indicates a. bushing which is adapted to be placed in the nozzle of a tuyre. The bushing 2 is preferably in the -form of a tapered cylinder having a bore 4 which is tapered in the same direction and at a greater angle than the outer surface of the bushing 2. The size of the bore 4 is determined by the volume and velocity of the blast required to blow the iurnace. As the velocity of air forced through 'a tuyre is directly dependent on the diameter of its nozzle, the air blast velocity can easily be Varied by inserting the bushing 2, which decreases the effective diameter of the tuyre, in the nozzle of the tuyre.

The invention contemplates constructing the bushing 2 in such a manner and from such material that the bushing 2 can be broken while in the tuyre when no longer required therein. Oi course, the bushing 2 must be strong enough to stand the ordinary shocks and heat attendant its installation and use in the tuyre. As the bushing 2 is but a temporary diameter reducer for a tuyre, it should be easily removable from the tuyre when no longer required therein. With this purpose in View, the bushing 2 is made frangible by cutting a plurality of grooves therein which -form weakened areas or zones in the Walls of the bushing. A plurality of longitudinally directed grooves 6 and a circumferential groove 8 may be cut into the walls of the bushing 2 in order to form the desired weakened zones and facilitate breaking the bushing into pieces of disposable size.

In Figure 2 of the drawing, the bushing 2 is shown positioned in a tuyre ID. The tuyre ID is of a standard design and mounted in the blast furnace by a tuyre cooler !2. A blow-pipe M bears on the rear of the tuyre li) and connects to a penstock IS. The penstock s is provided with a peep-hole il and a peep-hole cover !8 which are aligned with the blow-pipe [4. The penstock 16 is made to bear upon the blow-pipe i 4 by a hanger bolt 26 or other similar means. The blast of air required for the furnace is supplied by a bustle pipe (not shown) which is connected to the penstock i E. The air blast reaches the tuyre lil and the bushing 2 through the blow-pipe l4.

The tuyre lll is designed to furnish the Volume and velocity of air blast required for the normal production of the furnace. However, when this production is decreased, the air blast must be decreased and this is readily done by inserting the bushing 2 in the tuyre H), thereby reducing the blast while at the same time maintaining or if desired, increasing the velocity of the blast. In order to insert the bushing 2, the hanger bolt 20 must be loosened and the blow-pipe |4 removed. Then the bushing 2 can be inserted in the tuyre o and the blow-pipe !4 replaced, thus reducing the eective air passage through the tuyre and consequently increasing the velocity of the air blast as it enters the furnace.

The bushing 2 can be removed by a repetition of the steps required to insert it, or it can be broken while in the tuyre ID if desired. A rod or other means can be inserted through the peephole 11 and, by one or two well placed blows, break the bushing 2. The fragments of the bushing 2 can then be pushed into the furnace and the full blast of the tuyre Io restored;

It will be appreciated that the invention is not limited to the specific form illustrated and described, but is actually defined in the appended claims. i i

I claim:

1. A temporary diameter 'educer for a tuyre comprsng a hollow bushing of heat resisting ma.- terial and adapted to fit in a. tuyre, said bushing being provided with at least one longitudnaly and at least one circumferentially extending groove in the outer surface thereof forming Weakened zones for facilitating the breaking of said bushing.

2. A temporary diameter reducer for a. tuyre comprsing a bushing adapted to fit in a tuyre,

said bushing being composed of frangible heat resisting material and provided With at least one groove in the outer surface thereof forming Weakened zones for 'facilitating the breaking of said bushing.

3. A temporary diameter reducer for a tuyre comprisng a bushing composed of frangible heatresisting material and provided with a wall having indentations therein forming weakened. zones for facilitating the breaking of said bushing.

FREDERICK H. N. GERWIG. 

